油田集输管线的联合阴极保护

Cathodic Protection for Intensive Flowlines in Oilfields

外防腐层与阴极保护是油田集输管线最经济有效的防腐蚀措施,但是管线的阴极保护往往与油田地面设施的防雷/静电技术不匹配,管线的阴极保护效果受影响。文中介绍了采用联合阴极保护油田集输管线的极化水平不均的问题。从绝缘接头绝缘性、管线阻性以及站内地面设施接地等方面进行了阴极保护系统调查,指出绝缘接头失效、现有接地系统是导致电流漏失的因素。对集输管线原有阴极保护系统提出了在恒电位仪输出阴极串联具有强制分流的阴极接线箱、绝缘接头保护、接地改造等改进措施。

Coating combined with cathodic protection proves to be the most cost-economic anticorrosion measurement for oilfield intensive flowlines. The cathodic protection system,however,is normally incompatible with the grounding system of aboveground facilities,so the cathodic protection level is not acceptable. Uneven cathode polarization for intensive flow lines in oilfield is set forth,and the cathodic systems are investigated from insulation joints,coating conductance and grounding of the aboveground facilities,the cause of the failure of insulation joints down to the improper grounding system. The compulsory shunt in cathodic junction box connected with the cathode terminal of the transformer rectifier,the additional surge arrester for insulation joints from thunder lighting and grounding of aboveground facilities were proposed.